Wing structure



March14, 1939. 7 F1}; FLADER' 2,150,546

' WING. STRUCTURE Filed Oct. 14 1956 I 3 SheetS -Sheefc 1 Fiat IN VEN TOR.

FREDRIC E-ELADEIQ.

F. E. FLADER 1 WING STRUCTURE March 14, 1939.

3 Sheets-Sheet 2 Filed Oct. 14, 1936 INVENTOR. FREDRIC BFLADBR ATTO- March 14, 1939.

F. E. FLADER WING STRUCTUF'E':

Filed Oct. 14. 1936 3 Sheets-Sheet 3 INVENTOR. FREDRIC E. FLADEE.

Patented Mar. 14, 1939' UNITED STATE-:8.

PATELNT oFncl:

2,150,546 WING STRUCTURE Fredric E. l 'lader, Kenmore, N. Y., assignor, by mesne assignments, to (iurtiss-Wright Corporation, a corporation of New York v Application october 14, 1931;, sci-1A1 No. 105,4 2

'lClaim.

. This invention relates to aircraft and is particularly concerned with improvements in the wing and fuselage structure in. aircraft of that type in which the structural elements and covering are fabricated entirely from metal.

The type of aircraft to which this invention particularly relates is that which is known as a continuously from wing tip to wing'tip, 'due to the differential torque reactions on the wings at opposite sides of the fuselage. By making the whole wing unit a substantially unitary structure, attachment of the wing to the fuselage becomes a relatively simple matter and the differential torsional and lift reactions oneach side of the fuselage are then taken care of in the wing structure rather than in the attachment means of the wing tofuselage.

In suchua unitary wing structure, where the wing covering is utilized to assume part of the stress, it will be apparent that ordinarily it would be desirable to carry the stressed wing covering through the fuselage. However, the closed wingstructure within the fusela e takes up an amount of space which can be ii aiiorded, since itis as desirable to utilize this space for other purposes. In the present embodiment, it is desired to utilize part of the volumetric space of that part of the wing which is inside the fuselage for accommodation of the aircraft crew.

i a An object of the invention therefore is to provide means for forming that part of the cantilever wing which occupies an aircraft fuselage in such a manner as to provide increased available space 5 within the fuselage. A further object is to provide a stressed skin wing having braces in certain 'portions thereof to replace removed portions of the ;skin. Still a further object of the invention is to provide a novel form of composite wing spar.

50 A further object is to provide a box type wing spar, a part of which is adapted to. form, with. suitable partitions, tankage space for fuel. A further object-of the invention is to utilize the normal structural members of a wing to perform a dual functiomin-first assuming wing loads and bracing of this invention,

I second in forming the bordering-elements of a fuel tank.- 4

' An understanding of the details of the invention maybe gained by reading the annexedspecific description and in viewing the drawings in 2 which: Fig. 1 is a plan of the central part'of an aircraft wing and fuselage constructed according to the invention, v a

Fig. 21s a section-on the line 2-2 of Fig. 1, Fig. 3 is a perspective viewof a portion of the aircraft wing,

Fig. 4 is a fragmentary section on the line 4-4 I U of Fig. 1.

Fig. 5 is an enlarged fragmentary plan of the 15 central part of the wing structure including the Fig. 6 is a'sectiomon the line 66 of Fig. 5,

Fig. 7 is a section'on' the line 1-1 of Fig. 1,

Fig. 8 is an enlarged fragmentary section '20 through part of the'wing spar and, i

' Figs. 9 and 10 are sections on the lines 9-9 and Ill-l0 respectively of Fig. 8. v

Referring to the drawings. I provide a metal fuselage ll having a cantilever wing system I2 25 attached thereto, lateral wing portions I3 and II respectively extending out from the fuselage from substantially the middle part of said fuselage. The panels I 3 and i4 carry power plant units i5 and I6 in the conventional manner. 30

The wing system l2 comprises a main wing beam l1 extending between the power plant units l5 and I6, through the fuselage H, this-beam I i being located approximately per cent of the distance fromthe wing leading edge to the wing 35 trailing edge. An auxiliary wing beam I8 is located forward of the main-beam l1, both the beams I1 and. I8 comprising web plates l9 and 20 respectively provided with chord elements 2| and 22 respectively at their upper edges, and 23 and 24 respectively at their lower edges. The elements 2| and 22 are joined by a metal plate 25 and similarly, the elements 23 and 24 are joined by a metal plate 26, the plates 25 and 26 thereby forming, with the beams and It, a unitary box spar. The plates 25 and 26 also form a part of the outer airfoil section covering, the balance of the wing structure'extending rwardly and rearwardly from-the composite bo spar to form,

respectively, leading edge portions 21 and trailing edge portions 28. v I

It should be noted that the beams I1 and I6 extend continuously through the fuselage II and I as normally, practiced, the lower plate 26 between the beams may be left intact within the fuselage ll. However, the upper plate 25, joiningthe beams I1 and I8, is removed within the fuselage ll so that the space within the spar, within the fuselage, is available for use. It will be realized that the plate 25 serves a useful function as partof the wing. structure and since it is omitted within the fuselage, a skeleton bracing 23 is substituted therefor, so that torsional reactions between the panels i3 and, I4 may be assumed by the wing structure alone without these stresses being imparted to the fuselage. This bracing, as is best shown in Fig. 5, comprises tubular members 30 extending rearwardly and inwardly from the juncture of the chord 22 and the plate 25. Similarly, elements 3| extend inwardly and forwardly from the juncture of the chord 2| and the prises the principle structural element of the wing, the leading and trailing edge portions 21 and 28 being attached to the spar outside of the fuselage to comprise the required airfoil form of the wing system per se.

The wing system is attached to the fuselage, as shown in Fig. 7,.by suitable angle members v35 joined respectively to the fuselage covering and 23, and the beam webs 19' 36, the plates 25 and 20.

a It will'be appreciated that the webs l9 and 20 with the plates 25 and 26, outside of the fuselage, provide a strong boxiunit occupying a considerable volumetric space? This space may properly beutilized for fuel tankage for the aircraft by the provision of appropriate partitions 31 and 33, between the fuselage l l and the respective engine units l5 and I5. Figs. '7 to inclusive show the detailed attachment of the partitions 31 and 38 to the spar structure, the several joints involved being made liquid tight as is obviously necessary 1 for fuel tankage. In referring to Fig. 8 it will be noted that the beam' chord element 22 is grooved at 39 and 40, the grooves being covered by the plate 25 and the web 20 respectively. The grooves are then filled by suitable injection apparatus with a plastic compound to effect a fluid tight seal between the members. Similar grooves are provided in the other chord elements 2|, 23 and 24, so that fluid tight ,joints may be made thereat. Fig. 10 shows the typical means of attaching the partitions 31 (or 33) to theweb 20 (or to the plates 25 or 26, or to the web i9) The partition 31 is in end abutment with the web 20,

and angle members-ll and'4 2 are suitably attached as by rivets to the elements 31 and 2 0. The angle member 42 is formed with a large fillet so that when assembled a substantially triangular space 43 is formed by the several members which are joined together. After assembly of the various members, the space 43 is filled with a plastic composition to provide a fluid tight seal at the joint.

It will be understood that the same character of joint ismade throughout the periphery of the partitions 31 and 33. Stiffeners 44 are attached to the several members 31, 38, 25, 26, I9 and 20 to prevent bulging of these members under the weight of liquid fuel contained .in the tank. A conventional filler opening 45 may be provided for each tank, as shown in Fig. 3, and suitable drain and gauge fittings 46 may be let through the tank members and attached thereto.

In the above description the interference has been that the beams l1 and i8 extend continuously fromwing tip to wing tip. These beams may, if desired, extend only between the power units l5 and I6, and separate wing tip sections may be bolted to the ends of the beams in a manner well known in the art, to provide for more easy assembly, disassembly and storage of the aircraft. Such difference in construction, how- I ever, has no material effect upon the invention, the

essence of which is the provision of tankage space within the box spar, and the provision of a unitary central spar portion for the aircraft, capable of sustaining torsional loads which may be imposed thereon without the necessity of complicated joints and bracing organization. As previously pointed out this latter phase of the, invention provides useful space which might otherwise be occupied by the center part of the wing alone within the fuselage.

While I have described my invention in detail in its present preferred embodiment, it will be obvious to those skilled in the art, after understanding my invention, that various changes and modifications may be made therein without departing from the spirit or scope thereof. I aim in the appended claim to cover all such modifications and changes.

What I claim is:

In aircraft, a fuselage, main and auxiliary wing spars in spaced relation extending therethrough, and a skeleton bracing system,:,between said spars and within said fuselage, said system comprising members extending inwardly from the junctures of the spars and fuselage sides to intersections, and members extending from said intersections to the mid-point, between the fuselage sides, of one of said spars.

FREDRIC E. FLADER. 

